Global warming and increase of energy consumption issues has encourages architect to design energy efficient building. The most crucial aspect in designing building in warm humid climate is solar irradiance and wind flow. High level of irradiance increase heat gain of the building and it also cause a higher cooling load and cooling energy. More compact the building form, the cooling energy consumption will be less. Compact or bulky building usually consumes less cooling energy than the slim one because it has lower s/v ratio. Thus the bulky form, middle rise wide span building usually uses atrium to help distribute daylight in to every room of the building. Unfortunately the daylight from the atrium brings considerable heat because the solar radiation that hit the horizontal plane is very high and it’s very difficult to minimize solar gain in the roof. This research aims to evaluate the daylight performance of middle rise wide span building in Surabaya. Case study of this research is G-Building of Institute Technology Adhi Tama Surabaya.
To evaluate the daylight performance daylight factor of the building was measured by lux-meter and then compared to daylight factor standard for any rooms. Daylight performance of the buildings was found to bear some relations to cooling energy performance and composition of fenestration-opaque roof in atrium.